Flash freezes in Firefox 1.0

Hello,

I am having difficulty viewing Flash animations in Firefox 1.0 on Mac
OS X 10.3.7 on a PowerBook G4/800. My system has 512MB RAM and a 40GB
HD. When I visit:

<http://www.homestarrunner.com/yellodellomenu.htm>

My browser invariably freezes. The problem also seems to occur on
nightly builds of Mozilla (the suite). The site works fine in other
browsers (like Opera 7.5 and Safari 1.2). I also tried it on a Power
Mac G5 at work with Firefox 1.0 and it seemed to work OK. Is it just
that Firefox/Mozilla takes way too much processing power to play Flash
animations, or is there something in my configuration that I can fix?
Please help, it would be nice if I didn't have to open Opera just to
watch Flash movies!

Thanks in advance!